R need to replace text between slashes in URL

I'm trying to replace a number in a URL to improve image quality and can't figure out how to properly escape the / to get it to work.

I need to change://contentinfo.autozone.com/znetcs/product-info/en/US/nip/3289/image/1/ to://contentinfo.autozone.com/znetcs/product-info/en/US/nip/3289/image/10/

of course, https is ahead of both of those URLs, but the forum converts that to an image if I include it.

Working Solution, Thanks Aurèle!

sub("\d+/?$", "10/", myurl) – Aurèle